Every year it seems people grumble, “This is the worst allergy season ever.” But the Allergy and Asthma Foundation of America says it’s hard to determine year-to-year the severity of allergy season.

However, there are some explanations for why more Americans are being diagnosed with allergies.

• Climate change: Pollen levels are gradually increasing every year. Part of the reason is climate change. Warmer temperatures and milder winters can cause plants to begin producing and releasing pollen earlier, making the spring allergy season longer. Rain can promote plant and pollen growth, while wind accompanying rainfall can stir pollen and mold into the air, heightening symptoms.
• Priming effect: When the weather becomes erratic and regions experience unseasonably warm temperatures, an early release of pollen from trees triggers symptoms. Once allergy sufferers are exposed to this early pollen, their immune systems are primed to react to the allergens, meaning there will be little relief even if temperatures cool down before spring is in full bloom. This “priming effect” can mean heightened symptoms and a longer sneezing season for sufferers.
• Hygiene hypothesis: This theory suggests that exposure to bacterial byproducts from farm animals – and even dogs – in the first few months of life reduces or delays the onset of allergies and asthma. This may, in part, explain the increasing incidence of allergies worldwide in developed countries.

What are allergies?

Allergies reflect an overreaction of the immune system to substances that cause no reaction in most individuals. In people with allergies, however, these substances can trigger sneezing, wheezing, coughing and itching.

Allergies are not only bothersome, but many have been linked to a variety of common and serious chronic respiratory illnesses, such as sinusitis and asthma. Factors such as your family history with allergies, the types and frequency of symptoms, seasonality, duration and even location of symptoms (indoors or outdoors, for example) are all taken into consideration when a doctor diagnoses allergies.

With proper management and patient education, allergic diseases can be controlled, and people with allergies can lead normal and productive lives.